The following article features coverage from the American Society of Clinical Oncology 2019 meeting. Click here to read more of Hematology Advisor’s conference coverage.

Because of the 2014 diagnostic criteria revisions, including the removal of patients at the highest risk of progression, researchers presenting at the 2019 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, Illinois, reassessed the currently available risk models and developed a new risk stratification model for patients with smoldering multiple myeloma.

For the new model, researchers defined serum M protein (2 g/dL), involved to uninvolved serum-free light chain ratio (20), and marrow plasma cell percentage (20%) as the risk factors that are independently linked with disease progression. Although risk factors that have been used in previous models such as Bence Jones proteinuria and severe immunoparesis were deemed significant after univariate analysis, they were eliminated after stepwise regression. Patients considered to be at low risk had 0 risk factors, intermediate risk was defined as having 1 risk factor, and high risk was defined as having 2 or more risk factors.

Related Articles

“Compared to the low-risk group, intermediate- and high-risk groups had significantly higher rates of progression,” the study authors wrote. “Within the high-risk group, having all 3 risk factors (61 patients) compared with 2 [risk factors] did not add to the model, with insufficient separation between 2 and 3 factors.”

This model was based on a multicenter, retrospective study that included 2004 patients (ages 26-93 yars, 51% female) who were diagnosed with smoldering multiple myeloma during or after January 2004 and whose disease had not progressed within 6 months. In addition, patients needed to have baseline data from diagnosis, a year of follow up, and no enrollment in a clinical trial for their disease.

The researchers concluded that “additional analyses are being conducted to develop models that utilize common cytogenetic abnormalities, as well as those without free light chain given lack of availability of all tests across the world.”

Reference

1. San Miguel J, Mateos M-V, Gonzalez V, et al. Updated risk stratification model for smoldering multiple myeloma (SMM) incorporating the revised IMWG diagnostic criteria. Presented at: 2019 ASCO Annual Meeting; June 1, 2019; Chicago, IL. Abstract 8000.